Bones of the Cranium. 



Protvl. occip. 



3. Occipital Bone, Os occipitis, from below. 



3. and 4- C o n d y 1 o i d portions. On the upper surface (Fig. l) 

 the Processus anonymus ; on the lower surface both eondyloid processes 

 for articulation with the atlas ; behind these the flat eondyloid fossae. In 

 front of the eondyloid process lies the anterior eondyloid foramen (a short 

 canal for the XII. pair of cranial nerves). The posterior eondyloid foramen 

 is not always present (for an Emissarium Santorini). 



The inner border of the eondyloid portions forms the lateral border 

 of the Foramen magnum; the outer border shows the jugular notch, 

 Incisura juyularis, and at its posterior end the jugular process. The upper 

 surface of the process presents a groove (for the lateral sinus of the Dura 

 mater). 



The occipital bone articulates with 6 bones: with the 2 parietal 

 bones, the 2 temporal bones, with the sphenoid bone and with the first cervical 

 vertebra (atlas). 



